Energy and utilities

Estimate electricity use and costs, compare energy choices and convert common energy units.

• Electricity Cost Calculator

  Estimate an appliance’s daily and annual electricity use and cost.

• Appliance Upgrade Calculator

  Compare two appliances by annual energy cost, payback time and net savings.

• Electricity Bill Calculator

  Turn two meter readings into an estimated bill with fees and taxes.

• EV Charging Cost Calculator

  Estimate energy from the wall, charging time and cost for an EV session.

• EV vs Gas Cost Calculator

  Compare annual electricity and gasoline costs over the same distance.

• LED Savings Calculator

  Estimate energy and bill savings from replacing lamps with lower-wattage LEDs.

• Battery Runtime Calculator

  Estimate runtime from stored energy, reserve level, efficiency and load power.

• Energy Conversion Calculator

  Convert joules, watt-hours, kilowatt-hours, Btu and US therms.

• Solar Payback Calculator

  Estimate simple payback from solar cost, production and first-year benefits.

• Heat Pump vs Furnace Calculator

  Compare annual heat-pump electricity cost with gas-furnace fuel cost.

• Generator Fuel Cost Calculator

  Estimate generator fuel volume and cost from its stated hourly burn rate.

• Wind Turbine Power Calculator

  A wind turbine’s power at one wind speed, from its rotor size and power coefficient, with the Betz limit.

• Gas Appliance Running Cost Calculator

  What a propane or natural gas appliance costs to run an hour from its BTU rating, and how long a propane tank lasts.

• Pellet Stove Usage Calculator

  How many pounds and bags of wood pellets a stove burns a day and over a heating season, and what they cost, from its burn rate.

• Solar Panel Calculator

  How many solar panels it takes to cover your electricity use, from your kWh, the peak sun hours where you live, the panel rating and the system losses.